It's all relative humidity. Humidity changes when the temperature changes to stay relative. I have it happen in my humidor when temperature kinda' "drastically" changes, no biggie. What temp is it at when it was at 71* though. Mine usually bounces from 65-68ish when it gets like 3-4* colder. And humidty drops when it gets warmer. That's why 70/70 is not good for storage.